This variant most commonly used through the late 1980s and early 1990s.
The black cursive symbol handwritten near the stamp is a factory inspector's mark or a decorator's mark, added during quality control.
This plate is ironstone. Ironstone contains a dense mix of clay, flint, and feldspar. It was originally engineered in England during the 19th century as a sturdier, chip-resistant alternative to fine porcelain or bone china.
